The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Non-volatile semiconductor memory may include flash memory, static random access memory (SRAM), nitride read only memory (NROM), phase change memory, magnetic RAM, multi-state memory, etc. Non-volatile semiconductor memory may include hard defects or soft defects. Hard defects refer to defects that occur during manufacturing of a memory device and can be detected during an inspection process. Soft defects are defects that occur due to aging and use of a memory device (“wear and tear”).
Memory may be arranged in a hierarchy having levels. Memory defects may be associated with one or more levels of the hierarchy. A memory device may be divided into the levels of the hierarchy based on memory block size. Example levels in order of decreasing size include zones, sectors, pages, and/or arrays.
The hard defects may be detected and identified via scanning. The identification may include the location, type, and size of the portion of memory associated with the defect. In contrast, the soft defects are more difficult to detect since they occur over time during use.